Experimental FeatureReader that always takes the first column of the
attributeReader as the FeatureID. I want to get this working with postgis,
but then will consider other options, for those who want featureIDs created
automatically. Perhaps a constructor param or a method to say that you
would just like to have the FeatureReader increment one for each feature,
prepending the typeName. I'm also don't really like the one argument
constructor defaulting to the xxx typename. I feel that it should perhaps
take a typename. If people deliberately set to null then we could use xxx
or something. ch

This now feels sorta hacky, I'm not sure that I like it, but I'm going to
commit as I need to go now and revisit it in a bit. I think the idea of
passing in an FIDAttributeReader might be cleaner, and if none is provided
then do an auto-increment one. This might then work as the
DefaultFeatureReader.